body {
    margin: 0;
    padding: 0;
    overflow: hidden;
}
html, body {
    height: 100%;
    padding: 0;
    margin: 0;
    background: rgb(0, 0, 0);
}

canvas {
    position: absolute;
    width: 100%;
    height: 100%;
}

#child {
    position: absolute;
    left: 50%;
    top: 48%;
    transform: translate(-50%, -50%);

}

h4 {
    font-family: "STKaiti";
    font-size: 40px;
    color: #f584b7;
    position: relative;
}